"See to it that evil is not the last word. It (the last word) has to be hope," he said, according to Reuters. "Those who voluntarily take the road of evil rob a piece of hope. They rob it from themselves and from everybody, from society, from so many honest and hard-working people, they rob it from good name of the city and from its economy."

In a speech last year in Calabria the Pope condemned organised crime and excommunicated all members of the mafia.

In Naples, Francis defended the rights of immigrants, declaring they should not be considered "second-class human beings", called for fair wages for workers and railed against corruption.

"How much corruption there is in the world! I hope you have the courage… to clean up the city and clean up society so that there is no longer that stink of corruption," he said.

Later, Francis ate a meal with inmates in a notorious local prison, and said a Mass in the city's centre.